A rugged pattern (projections and recesses) may exist interiorly in a blood vessel at a blood vessel wall due to bulging of the blood vessel wall to the inside of the blood vessel, the bulging arising, for example, from a thrombus formed at the blood vessel wall, arterial sclerosis, plaque which is a macular hypertrophic lesion of an inner membrane present at a focus of arterial sclerosis, medial type calcification, etc. Depending on the extent of the ruggedness, stagnation or turbulence of blood flow may occur in hollows (recesses) of the rugged pattern, possibly leading to thrombus formation. As means for smoothening such a rugged pattern, there has been known a treatment using a catheter as disclosed in Japanese Application Publication No. 2011-509158.
The catheter described in Japanese Application Publication No. 2011-509158 is a medical device for treatment of plaque, and includes a catheter body and a freely inflatable and deflatable balloon assembly provided at a distal portion of the catheter body. In addition, the balloon assembly has a jet section for jetting a plaque removing agent. By use of this catheter, the following treatment is conducted.
First, the catheter is pushed forward in a blood vessel until the balloon assembly is located at a plaque. Next, the balloon assembly is inflated, and the plaque removing agent is jetted out from the jet section, to remove the plaque. Then, a stent is placed indwelling at that part of the blood vessel where the plaque has been removed. By this, the plaque is removed, and a sufficient inside diameter of the blood vessel can be secured.
Depending on the kind and extent of the rugged pattern formed in the blood vessel, however, it may be difficult to treat the rugged pattern by a treatment method in which the catheter as above-described is used. For example, in the above-mentioned treatment method, rugged patterns arising from a thrombus with diverse features such as size and shape of the rugged pattern generated at a blood vessel wall or arising from medial type calcification cannot be smoothened. Further, in a case where the extent of projections and recesses in the rugged pattern due to plaque is large, it may be impossible to insert the catheter and, therefore, it may be impossible to perform the intended treatment.